Reference is made to two U.S. patents directed to related subject matter. Markham, U.S. Pat. No. 4,774,948, filed Nov. 24, 1986 and issued Oct. 4, 1988, discloses a barbed stylet slidable in a windowed needle which permits withdrawal of the barb into the needle for retraction. Hawkins et al, U.S. Pat. No. 4,799,495, filed Mar. 20, 1987 and issued Jan. 24, 1989 discloses a similar barbed stylet and tubular needle with a side opening for projection and retraction of a stylet barb. A third and earlier patent, Ellison, U.S. Pat. No. 4,517,965, issued May 21, 1985, shows a tissue retractor needle with barbs which can be cammed out from the needle by an inner stylet.
The present invention has as an object the provision of a barbed stylet within a windowed needle and, in particular, control means for a surgeon to move the barbed stylet to a position of barb retraction and also to a position where the barb is projected out of the needle window into a localization position.